Laundry treatment apparatus

ABSTRACT

A laundry treatment apparatus is provided to improve energy efficiency by generating steam by a steam generating means using ultrasonic waves and reduce production costs and improve working efficiency by reduction of the number of heat suppliers by heating the generated steam by a heat supplier provided at a dryer. The laundry treatment apparatus includes a cabinet; a washing tub disposed inside the cabinet to treat laundry put therein; and an ultrasonic steam generating means for generating steam to be supplied into the washing tub by using ultrasonic waves.

This application claims priority from Korean Patent Application No. 10-2007-0100931, filed on Oct. 8, 2007 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a steam generating means which is used for a laundry treatment apparatus for treating laundry, such as a drum washing machine, a tower type washing machine, and a refresher.

2. Discussion of the Related Art

In general, a laundry treatment apparatus is commonly known as a washer which is an appliance for removing contaminants stuck to clothes, beddings and the like (hereinafter, referred to as “laundry”) by using a chemical decomposition of water and detergent and a physical action, such as friction between water and laundry and a refresher for washing laundry easily by jetting steam to the laundry.

Such laundry treatment apparatuses are divided into a tower type washing machine for doing laundry by friction between laundry by forming turbulence in wash water in a washing tub that is raised and a drum type washing machine for washing laundry by a physical impact generated by the rotation of the drum when the laundry put into a drum is lifted by a lifter formed in the drum and then dropped.

Recently, a laundry treatment apparatus having a steam generator for generating heated steam and applying the steam to laundry has been provided. Such a laundry treatment apparatus provides the function of easily washing laundry by jetting steam to the laundry, increases the solubility of a detergent by raising the temperature in the laundry and washing tub by adding a steam heating means, and makes contaminants stuck to the laundry swollen so that they can be easily removed during washing, thereby greatly improving washing performance. Thus, the demand thereof is increasing steadily.

By the way, a conventional steam wash-type steam generator employs the method of generating steam by using the phenomenon that water boils by heating, so a lot of energy is consumed to raise the temperature of water. However, it is not always necessary for the temperature in the washing tub to reach a water boiling point to achieve positive effects such as a sufficient solubility of detergent and an increase in the swelling of dirt of the laundry. Further, considerable time is required to heat water until boiling, thus lengthening the washing time.

Besides, since recent washing machines generally have a dryer for drying laundry, one heat supplier for use in a dryer and another heat supplier for use in a steam generator should be installed in the washing machine because a conventional steam generator employs the method of increasing the temperature of water for steam generation. This leads to the problem of an increase in the production cost of a washing machine.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a laundry treatment apparatus which can reduce fabrication costs by reducing components and improve energy efficiency by reducing energy consumption.

To achieve the above object, there is provided a laundry treatment apparatus according to the present invention, comprising: a cabinet; a washing tub disposed inside the cabinet to treat laundry put therein; and an ultrasonic steam generating means for generating steam to be supplied into the washing tub by using ultrasonic waves.

The laundry treatment apparatus may further comprise a steam heater for heating the steam generated by the ultrasonic steam generating means.

Preferably, the laundry treatment apparatus may further comprise a dryer for drying air to be supplied into the washing tub, the dryer being adapted to heat the steam generated by the ultrasonic steam generating means.

The dryer may further comprise a drying duct for inducing the flow of air and a heat supplier for supplying heat to the air passing through the drying duct to dry the air.

Preferably, the steam generated by the ultrasonic generating means may be heated by receiving heat from the heat supplier while passing through the drying duct.

Preferably, the dryer may further comprise a blower for sending the air dried by being passed through the heat supplier into the washing tub.

First, washing time can be shortened by reducing the steam generation time.

Second, the energy required for steam generation can be reduced because there is no need to heat water more than necessary for the generation of steam, and accordingly energy efficiency can be increased.

Third, steam heating time can be shortened by heating the steam to be supplied into the washing tub.

Fourth, costs can be reduced by a reduction of the number of heat suppliers because a heat supplier for heating steam can be shared with the dryer.

Fifth, it is possible to simplify an assembling process and reduce costs by simplification of the apparatus by providing a steam generating means in the dryer.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:

FIG. 1 is a perspective view illustrating a drum washing machine in accordance with a first embodiment of the present invention;

FIG. 2 is a cross sectional view taken along line II-II of FIG. 1;

FIG. 3 is a cross sectional view taken along line III-III of FIG. 1;

FIG. 4 is a cross sectional view of a steam generating means according to the present invention; and

FIG. 5 is a cross sectional view of a dryer according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, an embodiment of the present invention will be described by utilizing a drum washing machine as a primary apparatus. However, this is only for avoiding redundant description because the present invention is freely applicable regardless of the type of a laundry treatment apparatus. This invention can be commonly used for all laundry treatment apparatuses for treating laundry by means of steam, such as a tower type washing machine or a refresher for treating laundry by jetting steam.

Hereinafter, the present invention will be described with reference to FIGS. 1 to 5.

Hereinafter, a general view of a laundry treatment apparatus according to the present invention will be described with reference to FIGS. 1 to 3.

A washing machine 1 includes a cabinet 2 forming the outer appearance of the washing machine 1, a washing tub 40 installed in the cabinet 2 and performing washing of laundry, a driving source 5 mounted at the rear of the washing tub 40 and providing a driving force to be transmitted to the washing tub 40, a cabinet cover 8 mounted on the front surface of the cabinet 2 and having a laundry entrance 8A formed at the center, a door 10 rotatably installed on the cabinet cover 8 so as to open and close the laundry entrance 8A of the cabinet cover 8, a steam generating means 100 for supplying steam into the washing tub 40, a dryer 200 for drying laundry by providing dried air into the washing tub 40, and a detergent supplier 60 for supplying detergent into the washing tub 40 along with supplied water.

Although FIG. 3 illustrates the steam generating means 100 and the dryer 200 as being installed as separate devices, the present invention is not necessarily limited, but the steam generating means and the dryer may be provided and installed together within the same housing.

The washing tub 40 may include a tub 30 installed in the cabinet 2 so as to be damped by springs 12A and a damper 12B and containing wash water, a drum 20 rotatably installed in the tub 30 by the driving source 5 to hold laundry and having a plurality of through holes 20A through which wash water passes, and a lifter 22 installed on an inner surface of the drum 20 so that laundry can be lifted to a predetermined height and then dropped by gravity during the rotation of the drum 20.

Although the washing tub 40 has a structure having a drum and a tub because the present invention is described with respect to a drum washing machine, a washing tub of a laundry treatment apparatus of another type is not necessarily limited thereto.

A water supply device 80 forming a water supply passage of the washing tub 40 or steam generating means 100 is installed on the upper side of the washing tub 40. The water supply device 80 includes a water supply valve 82 installed in the cabinet 2 and controlling the flow of water introduced from the outside, and a water supply hose 84 whose one end is connected to the water supply valve 82 to guide water to the tub 30, steam generating means 100, and detergent supplier 60.

The steam generating means 100 is generally installed on an upper side in the cabinet so as to supply steam into the washing tub 40 in a steam washing or steam rinsing step. The steam generating means 40 is communicatively installed on the water supply passage formed between the water supply valve 82 and the washing tub 40, so that water W to be changed into steam is supplied to the steam generating means from the water supply device 80 via a water supply hose 130 for steam generation and the water is transformed into steam by using ultrasonic waves.

Hereinafter, the steam generating means 100 and dryer 200 of the present invention and a combination of them will be described concretely with reference to FIGS. 4 and 5.

Referring to FIG. 4, the steam generating means in accordance with a preferred embodiment of the present invention will be described. The steam generating means 100 includes a first water tank 160 for receiving and storing water supplied from the water supply device 80, a second water tank 170 which is a space for transforming the water supplied from the first water tank 160 into steam, a water level control valve 120 for controlling the water level of the second water tank 170 by adjusting the amount of water supplied from the first water tank 160, an oscillator for generating steam 150 by applying a high frequency oscillation to the water stored in the second water tank 170 so that fine particles of the water can splash over the water surface, and a steam supply pipe 140 for discharging the steam generated by the oscillation of the oscillator 110.

As stated above, the first water tank 160 and second water tank 170 can be provided at the steam generating means so that the level of the water covering the oscillator, of the water supplied from the water supply device 80, can be adjusted. This is because if the level of the water covering the oscillator 110 is too high due to a large amount of supplied water, the amount of the fine particles of the water emitted from the water surface may be decreased compared to the energy put to oscillate the oscillator 110 and thus the efficiency may be lowered. Accordingly, to overcome this problem, the steam generating means 100 may further include a water level control valve 120 consisting of a ball 124 and a spring 122 provided at the first water tank 160 and second water tank 170. Since the opening and closing of the valve can be controlled according to a water pressure difference between the first water tank 160 and the second water tank 170 by using the water level control valve 120, this enables the control of the water level of the second water tank 170. However, the water level control valve 120 is not limited to the above-described means, but any of well known water level control valves capable of controlling the water level of the second water tank 170 can be used.

The problem of water level control of the second water tank 170 can be overcome sufficiently by other means, including a method for restricting the level of water supplied by controlling of the water supply valve 82 provided at the water supply device 80 or controlling the height of the water tank. Therefore, it is not necessary to divide a water tank into two as illustrated in FIG. 4 to implement the present invention.

The oscillator 110 can fulfill its role only by transmitting ultrasonic waves to water to allow the fine particles of the water to be emitted from its surface, and there is no limitation in its shape or material. Also, although FIG. 4 illustrates the oscillator as being installed as a single unit, a plurality of oscillators may be installed in order to increase the amount of steam generation.

In the present invention, the method of generating steam by heating water up to a boiling point unlike the conventional art is not employed unlike the conventional art, but steam is generated in a manner that the fine particles of the water are ejected onto the water surface by the oscillation of the water molecules. Due to this, there is no need to raise the temperature of the water in order to generate steam, thus reducing the energy input amount for steam generation can be reduced, and there is no need to install a particular heat supplier for steam generation. Further, while the conventional steam generating means requires a waiting time because it generates steam after the water temperature reaches a boiling point, the present invention can shorten washing time because steam can be generated instantaneously when needed by using a means for generating steam by using ultrasonic waves.

Although the steam generating means 100 is illustrated as having no particular heat supplier installed therein, the present invention is not limited thereto. Though there will be a problem of cost increase, a steam generating means having a heat supplier for use in the steam generating means installed therein is also included in the scope of the present invention as far as it has the features of the present invention.

Hereinafter, the dryer 200 of the present invention and how the steam generated from the steam generating means 100 is generated and supplied into the washing tub 40 will be discussed.

The dryer 200 includes a steam valve 250 for controlling steam supplied from the steam generating means 100, an air intake valve 240 for sucking an outside air, a blower 210 for increasing the flow rate of the steam supplied from the steam valve 250 or of the air supplied from the air intake valve 240, a drying duct 230 for inducing the flow of the steam or air whose flow rate is increased by the blower 210.

First, a procedure for drying laundry by the air dried by the dryer 200 will be described. As the blower 210 of the dryer 200 rotates, this forms a low pressure at the air intake valve side. At this time, air is permitted to be sucked through the air intake valve 240 by opening the air intake valve 240 and closing the steam valve 250. The sucked air is heated by heat generated from the heat supplier 220 to thus lower the relative humidity, and the air is supplied into the washing tub 40 through the drying duct 230.

At this time, to dry laundry, air applied to the laundry should be dried as much as possible and its humidity should be lowered so that the air ejected to the laundry can dry the laundry by depriving the laundry of a sufficient amount of moisture. Due to this reason, it is necessary to prevent additional moisture from entering from the outside when reducing the relative humidity by sucking air and heating the air by the drier 200. By the way, since the dryer 200 is communicatively connected to the steam generating means 100, it is necessary to prevent the dryer 200 from sucking steam from the steam generating means when the dryer dries laundry. For this, it is preferable to perform a valve control such that the air intake valve 240 is opened and the steam valve 250 is closed in the procedure in which the dryer 200 supplies dried air to the washing tub 40. However, if the heat supplier 230 supplies enough heat even if the air intake valve 240 or the steam valve 250 is not controlled, it is not impossible to maintain a sufficient humidity by drying air by the use of a heat supplier even if the steam generated in the steam generating means is partially included in the air during air intake. Moreover, if the dryer 200 is operated in a state that the operation of the steam generating means 100 is stopped, steam introduced from the steam generating means 100 during the drying process of the air may become smaller and hence there may be no big trouble in drying laundry. Thus, the air intake valve or the steam valve is not necessarily required.

Although the blower 210 illustrated in FIG. 5 employs the method of sucking air or steam by rotating wings, the present invention is not necessarily limited thereto, and any means capable of sucking air and steam, such as a gear pump and a piston pump, can be applied without any limitation.

Further, although the heat supplier 220 may be a hot wire type as illustrated in FIG. 5, the present invention is not limited thereto and a heat pump or any other means capable of removing moisture by heating air can be applied. If there is a means capable of removing moisture from air by a chemical method, this means can replace the heat supplier 220. Thus, it is not necessary to essentially provide the heat supplier 220.

Hereinafter, a procedure for heating steam supplied from the steam generating means through the dryer 200 will be described. First, as the blower 210 rotates, this lowers the pressure at the steam valve 250 side. At this time, if the air intake valve 240 is closed and the steam valve 250 is opened, steam is introduced through the steam valve 250 because no air is introduced from the air intake valve 240. The introduced air passes through the heat supplier and is heated by receiving heat.

At this time, to sufficiently raise the temperature of the steam, it is possible to use a means for increasing the opportunity to receive heat from the heat supplier 220 by making the length of the drying duct 230 and the surface area contacting the steam of the heat supplier 220 larger compared to those illustrated in FIG. 5, or by forming the passage of the drying duct so as to reciprocate the heat supplier 220 a number of times. Accordingly, the present invention is not limited by the arrangement of the drying duct 230 or hot wire as illustrated in FIG. 5.

By the use of the steam generating means 100 of the present invention, a means for heating steam generated from the steam generating means 100 and a heater supplier, which is a means for heating air to dry laundry, can be integrated as the heat supplier 220 provided at the dryer 200. Due to this, there is no particular heat supplier required in the steam generating means which has been essentially required in the prior art. As a result, it is possible to reduce costs enough to cover the expense of the heat supplier, thus increasing price competitiveness. Besides, the size of the steam generating means 100 can be drastically decreased, and this effect of decreasing the size of the steam generating means 100 makes it possible to additionally secure a space for other devices and significantly increase assembly workability.

Although the present invention has been described in connection with the embodiment illustrated in the drawings, the embodiments are merely for illustrative purposes. It will be understood by those skilled in the art that various modifications and other equivalent embodiments can be made thereto. Therefore, the true technical scope of the invention should be construed as being defined by the appended claims. 

1. A laundry treatment apparatus, comprising: a cabinet; a washing tub disposed inside the cabinet to treat laundry put therein; and an ultrasonic steam generating means for generating steam to be supplied into the washing tub by using ultrasonic waves.
 2. The laundry treatment apparatus of claim 1, further comprising a steam heater for heating the steam generated by the ultrasonic steam generating means.
 3. The laundry treatment apparatus of claim 1, further comprising a dryer for drying air to be supplied into the washing tub, the dryer being adapted to heat the steam generated by the ultrasonic steam generating means.
 4. The laundry treatment apparatus of claim 3, wherein the dryer further comprises a drying duct for inducing the flow of air and a heat supplier for supplying heat to the air passing through the drying duct to dry the air.
 5. The laundry treatment apparatus of claim 4, wherein the steam generated by the ultrasonic generating means is heated by receiving heat from the heat supplier while passing through the drying duct.
 6. The laundry treatment apparatus of claim 4, wherein the dryer further comprises a blower for sending the air dried by being passed through the heat supplier into the washing tub.
 7. The laundry treatment apparatus of claim 1, further comprising: a dryer for drying air supplied into the washing tub and heating the steam generated by the ultrasonic steam generating means, the ultrasonic steam generating means and the dryer being disposed in the same housing.
 8. The laundry treatment apparatus of claim 1, further comprising: a water supply device disposed in the cabinet for introducing wash water into the washing tub from the outside, the ultrasonic steam generating means, being disposed in the water supply device, for generating the steam from the wash water introduced into the washing tub.
 9. The laundry treatment apparatus of claim 8, wherein the water supply device comprises: a water supply valve disposed in the cabinet for controlling the flow of the wash water introduced from the outside; and a water supply hose whose one end is connected to the water supply valve to guide water to the washing tub, the ultrasonic steam generating means being disposed between the water supply valve and the washing tub, the ultrasonic steam generating means generating the steam from the wash water flowing through the water supply hose.
 10. The laundry treatment apparatus of claim 1, wherein the ultrasonic steam generating means is disposed on the upper side of the cabinet.
 11. The laundry treatment apparatus of claim 1, further comprising: a water supply device, disposed in the cabinet, for introducing wash water into the washing tub from the outside, the ultrasonic steam generating means comprising: a first water tank for receiving and storing wash water supplied from the water supply device; a second water tank for transforming the wash water supplied from the first water tank into steam; a water level control valve, communicating between the first water tank and the second water tank, for controlling the level of the wash water of the second water tank by adjusting the amount of the wash water supplied from the first water tank; an oscillator for applying a high frequency oscillation to the wash water stored in the second water tank; and a steam supply pipe, connected to one side of the oscillator, for discharging the steam generated by the oscillation of the oscillator.
 12. The laundry treatment apparatus of claim 11, wherein the water level control valve comprises: a water pressure ball, disposed in the first water tank, for receiving the water pressure of the first water tank; and a water pressure control spring, positioned behind to the water pressure ball, for withstanding the water pressure transmitted from the water pressure ball.
 13. The laundry treatment apparatus of claim 11, wherein the water level control valve controls the water level of the first water tank and second water tank by metering water from the first to the second tank according to a water pressure difference between the first water tank and the second water tank. 